Wouldn't this have the opposite affect, though. The chances of surviving a body shot are much greater than a head shot. From now, shooters will assume a vest and aim (better) to the head, and perhaps train to be better marksmen in order not to miss (or get closer to the target.)

It's down to trade-offs again i guess, i agree if a shooter knows he is wearing a vest, they will go for his head. A harder shot to make however. A poorly aimed, rushed shot could go anywhere, and its playing the odds to wear body armour as there is more chance of taking one in the torso as opposed to the head. Not a perfect solution, but better than nothing.

Criminals may well aim for the head if they think you're wearing a vest, but the fact is that between the "Gangsta Grip", "spray and pray", and the lack of anything resembling range practice, most criminals can barely hit a barn from the inside with a pistol, much less hit someone in the head other than standing behind them at point-blank range.

i'm not an expert on defensive clothing, but i question whether any clothes are truly "bulletproof". i believe it depends on the energy of the bullet (the mass times the square of the velocity), that the term "bullet-resistant" may be more accurate, and that if i'm using an unusually powerful gun, e.g., the s&w .50 magnum, i can shoot through your kevlar vest.
there's a big scandal now involving "second chance", a maker of defensive clothing which failed to inform its customers that the miracle substance in the vests degrades over time, exposing its wearer to bullets, and at least one cop has died because of this.

In my days I heard stories of one rifle slug which passed through a ceramic vest, through the flesh, through the vest again, the air, and a third time through the vest, to remain lodged inside someone's body. It was a 5.56 bullet fired by an M-16.

Not just pellets, but bullets tend to break apart when they enter your body and cavitate. Blunt trauma is horrible, but being sliced and diced internally is usually worse.

Since bullets tend to break-apart after entry and lose velocity/direction, I was getting curious about Arik's post and ran into this paper on the effects of a 4.0g NATO 5.56 mm calibre bullet on ceramic armor:

It is a known fact that Troops in the Middle East wear body armour. What the terrorists have done to over power the body armour is to use a large caliber weapon to either punch through the body armour or as one person has talked about transfer so much shock/force to the body that flesh and organs behind the impact point are severely traumatised and the person dies from said injuries.

There have been cases reported where it appears as if individuals with body armour on were targed with Rocket Propelled Grenades in the Middle East as well.

For heads of state, such as Chavez, all you need is a big enough entourage of lackeys wearing vests like this one around you, and it will provide all the stopping force you need. 3 concentric circles of people wearing pretty good vests = 1 really good vest, as long as they don't hit the dirt before you do.

To the physics-challenged individuals who talk of death from the "force" of being hit by a non-penetrating shot: Do you also think that the shooters suffer near-terminal injuries each time they pull the trigger? After all, the bullets do not magically gain momentum midair: they are not rockets. (Sure, on semiauto/fullauto weapons the ejection-rechambering cycle takes some of the impact away, and dulls the rest, but other types of guns can be discharged without deadly effects as well.)

That's the whole point of spreading the force. The target is still going to have to eat the momentum of the bullet - no amount of padding will give you an exception to Newton's laws - but the vest is supposed to spread it across a large enough area not to do serious damage. The design of the weapon performs a similar function at the shooter's end of things - the recoil is distributed across the whole grip, at what's supposed to be a harmless level per unit area.

Talk about life imitating art. A number of, ahem, dystopian near-future cyberpunk role playing games have for some time described body armour produced by fashion houses. Essential kit if you're going to a really nice restaurant to meet someone you really don't trust. Of course I only know this because someone told me...

"I'd be more impressed if he had his employees shoot him. They'd probably like it better too."

The president of at least one body armour company used to do exactly that. Can't recall which one off the top of my head, but saw the video.

"Well, a fair point, but shooters don't exactly "pull the trigger" so the force impacts their head or the blunt of their chest do they?"

They may do if they're novices and stuff it up. The worst result is moderate bruising. Of course the blow from a projectile tends to be concentrated over a smaller area; cracked ribs are a possibility, but not much more.

I wrote: "Of course the blow from a projectile tends to be concentrated over a smaller area; cracked ribs are a possibility, but not much more."

Hmm, that's a little too glib. I should say, for the soft armours commonly encountered, using a projectile for which the vest is rated, a single shot which is intercepted by the vest, is unlikely to do more than crack ribs. But there a few caveats in there, the most important of which is that no practical field armour covers the whole body.

And addressing the post that started this sub-thread:
"There have been cases reported where it appears as if individuals with body armour on were targed with Rocket Propelled Grenades in the Middle East as well."

More likely a lucky shot. RPGs are not really accurate enough to target individual persons. With any sort of reasonable wind going, even when aiming at a _tank_ hit probability drops to 50% at ~150 metres. Of course a near miss will shower you with fragmentation, but body armour does provide some protection from that.

@GunNut
The reason it's not harmful to fire a gun is that the reaction force is not directly applied to the shooter. It is applied on the gun itself, which masses considerably more than the bullet. That force has to move the gun, overcoming it's inertia. The gun then exerts a somewhat dissipated force on the user, spread over the much larger contact area of the grip. That remaining force is safely absorbed by wrist and arm motion. Consider the fact that people have died from non-penetrating beanbag rounds, albeit at close range, while the shooter remained unharmed.

A not uncommon sniper weapon is a single shot 50 Caliber rifle. (The Canadian Special Forces use them) If you take a chest shot from 500 meters and the round is stopped (very debateable) how much damage to the chest, ribs, heart and other organs will be done by the kinetic energy absorbed by the body.

Don't most Handguns & rifles have buffers or buffergroups? You know, a series of springs or other such recoil absorbing devices built-in to it in order to minimize recoil impact on the person firing the weapon? I know they do in an M-16, I used to have to field strip them quickly for time.

"In the United States, body armor levels are certified by the National Institute of Justice (NIJ), which is an agency of the U.S. Department of Justice. The levels are I, II-A, II, III-A, III, and IV. Based on extensive laboratory tests, researchers classify any new body-armor design into one of seven categories: Category I body armor offers the lowest level of protection, and category IV offers the highest. The body-armor classes are often described by what sort of weaponry they guard against. The lowest-level body armor can only be relied on to protect against bullets with a relatively small caliber (diameter), which tend to have less force on impact. Some higher-grade body armor can protect against powerful shotgun fire. Categories I through III-A are soft and concealable. Type III is the first one to utilize hard or semi-rigid plates"

Direct quote from howstuffworks.com

If it is graded for a certain caliper weapon then that means it has been throughly tested and when shot with that weapon it will create no significant injuries. So basically if it is rated for it then that means blunt force trauma will not be an issue within the limit of the guns power and caliper.

What I'd like to see are bulletproof visors. What can class IV defend against? Will it stop 4 mm, 5.56x51 mm, 7.62x51, and 12.5 mm (.50 calibre)? If so, how much damage/bruising will it cause? Will it protect against standard fragmentation grenades from less than 2m radius? What about direct hits from rocket launchers? And of course the splash damage. Can this armour cover your entire body?

I've heard informal claims that helmets (including the visors) used in Formula 1 auto racing are "bulletproof".
This ballistic protection is not motivated by fear of armed attack, but rather by the range of kinetic energies of fragments that can result from crashes at high speeds.
In formula racing, the driver's heads are exposed (no roof), so the helmet is the only line of defense.